1. Field of the Invention
This invention relates to a weightlifting apparatus. More particularly, it relates to a weightlifting barbell with rotational grips.
2. Description of the Prior Art
Weightlifting is an increasingly popular form of exercise. In weightlifting, barbells are used to lift and pull various weights. Barbells typically include various types of bars having a bent structure to accommodate a variety of grasping orientations, as disclosed in U.S. Design Pat. No. D287,526.
Weight training exercises can also be performed using dumbbells. Since one dumbbell is held in each hand, a user can freely rotate the wrist and hand throughout the full range of motion as an exercise is performed. For example, in performing a shoulder press with dumbbells, a user holds a dumbbell in each hand directly beside the shoulders, with the palms facing toward each other. Then the dumbbells are raised over the head, and the palms are rotated to face forward. Finally, the palms are rotated back to the starting position as the weights are lowered.
The same exercise cannot be performed with a conventional barbell because the hands and wrists are in a fixed position. Thus, it is not possible to use a conventional barbell to exercise the groups of muscles involved in pronation and supination as with dumbbells. Moreover, maintaining such a fixed position during exercises with the barbell increases strain on the wrists and elbows.
Prior art devices have attempted to impart some grip rotation to the conventional barbell. In particular, U.S. Pat. Nos. 3,384,370, 4,618,183, 4,629,184, 5,334,113, 6,022,300, 4,585,229, 7,094,186, 4,690,400, 5,211,616, Re. 33,218, and U.S. Pat. App. Publication No. 20080176723 all discuss barbell arrangements having handgrips that are rotatably supported so that their angle relative to the bar may be adjusted.
While these devices address the need for a rotational grip barbell, the designs of these devices create a high level of friction and instability. Particularly, the configuration of these devices results in metal-on-metal contact or the bearings do not address sidewall loads on the grip housings. The friction and instability causes the grips to freeze or stick in place, presenting a significant risk of injury.
Moreover, the prior art does not address the need for a rotational grip barbell that is adapted to utilize cable exercise equipment.
However, in view of the prior art considered as a whole at the time the present invention was made, it was not obvious to those of ordinary skill in the art how the limitations of the art could be overcome.